192658 - Setting parameters for BW systems

Symptom

You want to set the Business Warehouse System (BW) basis parameters. The BW basis parameters must be set optimally for the BW system to work without errors and the system to perform efficiently.  The recommendations for BW systems are not always the same as those for R/3 systems.

Other Terms

Memory Management, EarlyWatch, GoingLive, Release 1.2B, Release 2.0A,
Release 2.0B, Release 2.1C, Release 3.0A, Release 3.0B, Release 3.1
Release 3.5, Releases 7.x

Reason and Prerequisites

The recommendations for BW systems are not always the same as those for R/3 systems. This note describes the differences between the parameter settings of a BW system and an R/3 system. Therefore, this note supplements Note 103747 for BW systems (Performance 4.0/4.5/4.6: Parameter recommendations). As with the recommendations in Note 103747, the recommendations here are intended as initial settings before you start using the system productively. After going live, you must adjust the individual parameters as required and adapt them to the actual requirements.

Number and type of work processes
This note does not contain any recommendations about the number and type of work processes. You can receive work processes tailored for your system from the recommended remote services. However, if you have not received any recommendations from the GoingLive services, you have to set up a minimum of six dialog work processes and three batch work processes.


This note is valid only for BW 1.2B, BW 2.0A, BW 2.0B,
BW 2.1C, BW 3.0A, BW 3.0B, BW 3.1, BW 3.5 and BI 7.x

For NetWeaver 2004s  or BI 7.0, see also Note 1044441.

Solution

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*  Support by Support Services                                          *
**********************************************************************
To ensure that the system performs efficiently after you start using it productively, we recommend you use the support services, for example, the GoingLive check for BW systems or an EarlyWatch contract for BW systems. With a GoingLive check for BW systems, you should schedule two sessions for 4-6 weeks before you start using the system productively and one session 4-6 weeks after you have started using the system productively.

TO AVOID LONG WAITING TIMES FOR A SERVICE SESSION APPOINTMENT, BOOK IN SUFFICIENT TIME BEFORE YOU START USING THE SYSTEM PRODUCTIVELY. TO DO THIS, CONTACT YOUR LOCAL SUPPORT.

This note supplements Note 103747  (Performance 4.0/4.5/4.6: Parameter recommendations) for BW systems. It describes the different parameter settings of a BW system and an R/3 system.

Recommendations given in Note 103747 for R/3 systems that are different for BW systems:

1a. Export/import buffer
BW 1.2B:
This buffer is frequently used in BW systems so the export/import buffer must be set to at least 10 MB. If you work with large hierarchies, you have to increase the size of this buffer considerably. You should be able to store at least 5,000 objects in the buffer.
rsdb/obj/buffersize                          10000 or higher (10 MB)
rsdb/obj/max_objects                          5000 or higher (entries)
rsdb/obj/large_object_size                10000 (10 MB)

BW 2.X: The buffer should be set to the size recommended for R/3 4.6 systems (see Note 103747).

BW 3.X: The buffer should be set to a larger size than the buffer for BW 2.X.

rsdb/obj/buffersize                          40000 or higher (40 MB)

1b. Export/import buffer SHM
BW 3.X ONLY (OLAP cache):
Parameter name             Value     Description
rsdb/esm/buffersize_kb     40000 or higher   Size of exp/imp SHM buffer (kB)
rsdb/esm/max_objects       10000     Maximum number of objects in buffer


2. Program buffer (abap/buffersize)
Depending on the size of the main memory, the program buffer should be between 200 and 400 MB. Unlike in R/3 Systems, a higher number of program buffer swaps is less important in BW Systems and is often unavoidable since the information stored in the program buffer is significantly less likely to be reused.  While the response times of R/3 transactions is only around several hundred milliseconds, the response times of BW queries takes seconds. However, by tuning the program buffer, you can only improve the performance by milliseconds.
Therefore, if the available main memory is limited, you should increase the size of the extended memory. However, the program buffer should not be set lower than 200 MB. If the available main memory is sufficient, the program buffer in BW 2.X/3.X systems should be set to at least 300 MB.

3. Extended Memory
BW users require significantly more extended memory than R/3 users. The size of the extended memory is related to the available main memory but should not be lower than 512 MB.

4. Single Record buffer
BW 2.X & 3.X: The buffer should be set to the size recommended for R/3 4.6 systems (see Note 103747).
Limits for BW 2.X:
You must also see Note 414220 with regard to the setting of the
parameters rtbb/max_tables, rtbb/buffer_length.
You must not exceed certain limits.
Limits for BW 3.X:
See Note 480710.

5. Recommendations for the 64-bit R/3 kernel
In addition to the recommendations from Note 146289, set the following parameter specifically for BW:
            em/blocksize_KB      4096

6. Maximum runtime for a work process
Set a higher runtime than is usual for R/3 systems:
rdisp/max_wprun_time                          3600

7. Connection to the front end
To avoid connection terminations, set the gw/cpic_timeout parameter to a sufficiently large value:
gw/cpic_timeout                                60

8. Further CPIC/RFC settings
   gw/max_conn                    2000
   gw/max_overflow_size       25000000
   rdisp/max_comm_entries         2000
   Because of the high RFC load, see the
   recommendataions from Note 74141.

9. Oracle Database Interface
Set the parameter dbs/ora/array_buf_size to a sufficiently large size to keep the number of array inserts, for example, when you upload data or during the rollup, as low as possible. This improves the performance during insert operations. Depending on the size of the available main memory, set the parameter dbs/ora/array_buf_size to a value of 1000000 (1MB).
dbs/ora/array_buf_size             1000000

10. Internet Communication Manager (ICM) Parameter
icm/host_name_full                <fully qualified name>
                                  You use this parameter to specify
                                  the fully qualified host name of the
                                  of the host on which the ICM is
                                  running. If this parameter is
                                  not set, the system queries the
                                  system for the host name.
                                  With several host names, this
                                  parameter can override this value.
SAPLOCALHOSTFULL                  <fully qualified name>
General timeouts:
icm/keep_alive_timeout             3600
                                  This parameter refers to the
                                  "keep-alive-feature" of HTTP1.1
rdisp/plugin_auto_logout           3600
                                  The user context is closed only after
                                  this time interval
Kernel Release 6.20
icm/server_port_: PROT=<xxxx>,PORT=<xxxx>,TIMEOUT=3600
                                  Defines keep_alive_timeout per port
                                  binding
Kernel Release 6.40ff
icm/server_port_: PROT=<xxxx>,PORT=<xxxx>,TIMEOUT=60, PROCTIMEOUT=3600
icm/keep_alive_timeout = 60

Further information:
Note 622629: Procedure when timeouts occur in BW Web Reporting
Note 622130: Timeout problems in BW Web Applications
Note 538405: Composite SAP Note on the SAP Web Dispatcher
11. Notes for configuring the databases
BW and R/3 Systems can differ significantly in terms of the configuration of the database.
The following notes contain recommendations for setting the database in a BW system:
                        0632556 Oracle 9.2.0.* database parameterization for BW
                    0632427 Oracle 8.1.7* database parameterization for BW
                    0180605  Oracle database parameter settings for BW
Informix            0114884 Performance Guide:  BW 1.2B on Informix
                    0181945 Performance guide: BW 2.0X & BW 3.0X
MS SQL Server        0142334 Installation BW 1.2B on MS SQL server
                    0209596 Setting up Microsoft SQL Server 2000
DB2 UDB Unix/Windows 0374502 DB6: BW performance: Note overview
                    0546262 DB6: Performance on SAP BW 3.0B
DB2 UDB OS/390       0390016 DB2/390: BW: Database settings and
                            performance
DB2 UDB AS/400       541508  iSeries: Checking the system parameters for BW

12. Essentials for parameter settings
- Save your old profile before you make any changes. If the instance does not start with the new parameters, you can use the old profile.
- Check all parameter settings before you use them (program sappfpar, in the test system, and so on).
- Take into account limitations due to the architecture of the operating system (for example, shared memory limitations). Errors and terminations may occur if you do not take these limitations into account.
  Bear in mind that concrete recommendations for parameter settings using TTC can only be given during a session service. ***********************************************************************
IMPORTANT:
  If the settings in the R/3 memory areas (R/3 buffer, R/3 extended memory and so on)
  are too small, unnecessary performance problems can occur.
    If the settings are too large, errors may occur when you start the
  R/3 instance, or runtime errors may occur.
  The optimal settings depend on the hardware (CPU and RAM), the R/3 release
  and the operating system release.
  The TCC services GoingLive and EarlyWatch provide recommendations tailored to your system.